Is Hotmail in the habit of ignoring MX records?
mysidia at gmail.com
Thu Jul 26 07:38:31 UTC 2012
On 7/26/12, Lou Katz <lou at metron.com> wrote:
> One of my users has reported incoming mail failures, which I finally
> tracked down. It turned out that Hotmail has seen fit to send the mail
> to his domain's A record machine, despite the fact that he has valid MX
You looked in the mail headers and saw hotmail's mail server do that,
or the From address/return path just happens to be hotmail?
I would ask for a specific example of a domain name in which that
seems to happen, and exact DNS zone contents.
I am sure that Hotmail does not ignore MX in general, unless they
just broke something; many domains require MX processing and A record
to properly be ignored for mail to be accepted. But there may be
something else going on with a specific domain or DNS
queries/responses from its nameservers, that results in MX being
ignored or unavailable, resulting in a fallback to 'lookup A'.
An example could be some dns issue such as slow response to MX query,
'MX to a CNAME', 'MX to an invalid label that looks like an IP', MX
DNS response packet too large,
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